package com.gene.utils;

import java.io.IOException;
import java.io.InputStream;
import java.net.MalformedURLException;
import java.net.URL;
import java.util.Properties;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;

public class ClassLoaderUtil {
	private static Log log = LogFactory.getLog(ClassLoaderUtil.class);

	/**
	 * Thread.currentThread().getContextClassLoader().getResource("")
	 */

	/**
	 * 加载Java类。 使用全限定类名
	 * 
	 * @paramclassName
	 * @return
	 */
	public static Class loadClass(String className) {
		try {
			return getClassLoader().loadClass(className);
		} catch (ClassNotFoundException e) {
			throw new RuntimeException("class not found '" + className + "'", e);
		}
	}

	/**
	 * 得到类加载器
	 * 
	 * @return
	 */
	public static ClassLoader getClassLoader() {
		return ClassLoaderUtil.class.getClassLoader();
	}

	/**
	 * 提供相对于classpath的资源路径，返回文件的输入流
	 * 
	 * @paramrelativePath必须传递资源的相对路径。是相对于classpath的路径。如果需要查找classpath外部的资源，需要使用.
	 * ./来查找
	 * @return 文件输入流
	 * @throwsIOException
	 * @throwsMalformedURLException
	 */
	public static InputStream	getStream(String relativePath) throws MalformedURLException, IOException {
		if (!relativePath.contains("../")) {
			return getClassLoader().getResourceAsStream(relativePath);

		} else {
			return ClassLoaderUtil.getStreamByExtendResource(relativePath);
		}
	}

	/**
   *
   *@paramurl
   *@return
   *@throwsIOException
   */
 public static InputStream getStream(URL url)throws IOException{
     if(url!=null){
            return url.openStream();
     }else{
         return null;
     }
 }
	/**
	 *
	 * @paramrelativePath必须传递资源的相对路径。是相对于classpath的路径。如果需要查找classpath外部的资源，需要使用.
	 * ./来查找
	 * @return
	 * @throwsMalformedURLException
	 * @throwsIOException
	 */
	public static InputStream getStreamByExtendResource(String relativePath) throws MalformedURLException, IOException {
		return ClassLoaderUtil.getStream(ClassLoaderUtil.getExtendResource(relativePath));

	}

	/**
	 * 提供相对于classpath的资源路径，返回属性对象，它是一个散列表
	 * 
	 * @paramresource
	 * @return
	 */
	public static Properties getProperties(String resource) {
    Properties properties = new Properties();
    try {
      properties.load(getStream(resource));
    } catch (IOException e) {

	throw new RuntimeException("couldn't load properties file '"+resource+"'", e);
    }return properties;}

	/**
	 * 得到本Class所在的ClassLoader的Classpat的绝对路径。 URL形式的
	 * 
	 * @return
	 */
	public static String getAbsolutePathOfClassLoaderClassPath() {
		ClassLoaderUtil.log.info(ClassLoaderUtil.getClassLoader().getResource("").toString());
		return ClassLoaderUtil.getClassLoader().getResource("").toString();

	}

	/**
	 *
	 * @paramrelativePath 必须传递资源的相对路径。是相对于classpath的路径。如果需要查找classpath外部的资源，需要使用
	 *                    ../来查找
	 * @return资源的绝对URL
	 * @throwsMalformedURLException
	 */
	public static URL getExtendResource(String relativePath) throws MalformedURLException {
		ClassLoaderUtil.log.info("传入的相对路径：" + relativePath);
		// ClassLoaderUtil.log.info(Integer.valueOf(relativePath.indexOf("../")))
		// ;
		if (!relativePath.contains("../")) {
			return ClassLoaderUtil.getResource(relativePath);

		}
		String classPathAbsolutePath = ClassLoaderUtil.getAbsolutePathOfClassLoaderClassPath();
		if (relativePath.substring(0, 1).equals("/")) {
			relativePath = relativePath.substring(1);
		}
		ClassLoaderUtil.log.info(Integer.valueOf(relativePath.lastIndexOf("../")));

		String wildcardString = relativePath.substring(0, relativePath.lastIndexOf("../") + 3);
		relativePath = relativePath.substring(relativePath.lastIndexOf("../") + 3);
		int containSum = ClassLoaderUtil.containSum(wildcardString, "../");
		classPathAbsolutePath = ClassLoaderUtil.cutLastString(classPathAbsolutePath, "/", containSum);
		String resourceAbsolutePath = classPathAbsolutePath + relativePath;
		ClassLoaderUtil.log.info("绝对路径：" + resourceAbsolutePath);
		URL resourceAbsoluteURL = new URL(resourceAbsolutePath);
		return resourceAbsoluteURL;
	}

	/**
	 *
	 * @paramsource
	 * @paramdest
	 * @return
	 */
	private static int containSum(String source, String dest) {
		int containSum = 0;
		int destLength = dest.length();
		while (source.contains(dest)) {
			containSum = containSum + 1;
			source = source.substring(destLength);
		}
		return containSum;
	}

	/**
	 *
	 * @paramsource
	 * @paramdest
	 * @paramnum
	 * @return
	 */
	private static String cutLastString(String source, String dest, int num) {
		// String cutSource=null;
		for (int i = 0; i < num; i++) {
			source = source.substring(0, source.lastIndexOf(dest, source.length() - 2) + 1);
		}
		return source;
	}
	/**
	 *
	 * @paramresource
	 * @return
	 */
	public static URL getResource(String resource) {
		ClassLoaderUtil.log.info("传入的相对于classpath的路径：" + resource);
		return ClassLoaderUtil.getClassLoader().getResource(resource);
	}

	/**
	 * @paramargs
	 * @throwsMalformedURLException
	 */
	public static void main(String[] args) throws MalformedURLException {
		// ClassLoaderUtil.getExtendResource("../spring/dao.xml");
		// ClassLoaderUtil.getExtendResource("../../../src/log4j.properties");
		ClassLoaderUtil.getExtendResource("../../webContent/fileManager");
		System.out.println(ClassLoaderUtil.getClassLoader().getResource("file.json").toString());

	}

}